Seatbelt monitoring systems are known that determine whether a passenger's seatbelt is latched after the occurrence of an event indicative of vehicle occupancy (e.g., ignition). If it is determined that the seatbelt latch has not been fastened, the seatbelt monitoring system may generate an indicator alert, such as a warning light mounted on the instrument panel, to indicate to the driver of the vehicle that a passenger may not be properly buckled in.
With the introduction of reconfigurable seat assemblies (e.g., removable second and third row bench seats), a need has developed for a seatbelt monitoring system that is capable of being contained within the seat assembly (e.g., being integrated into the seatbelt's buckle) and that wirelessly communicates with a controller connected to the vehicle's electrical infrastructure. To satisfy this need, a wireless seatbelt monitoring system has been introduced that includes a wireless transmitter, a piezoelectric element, and a micro-switch, which is open until the seatbelt's tongue is inserted into the seatbelt buckle. When inserted into or withdrawn from the seatbelt buckle, the seatbelt's tongue contacts and imparts mechanically stress to piezoelectric element. In response to this mechanical stress, the piezoelectric element generates a voltage, which is applied to the wireless transmitter. The transmitter utilizes this voltage, along with input from the micro-switch, to transmit a wireless signal (e.g., a radiofrequency signal) indicating the current latch status of the seatbelt (i.e., whether the seatbelt latch is fastened or unfastened). A processor associated with the vehicle (e.g., associated with the body control module) receives this wireless signal and, upon determining that the seatbelt is currently unlatched, generates an unlatched seatbelt alert (e.g., illuminates a warning light).
Although well suited for vehicles equipped with reconfigurable seat assemblies, wireless seatbelt monitoring systems of the type described above are limited in certain respects. For example, such seatbelt monitoring systems may generate an unlatched seatbelt alert at undesirable times (e.g., when the seat associated with an unlatched seatbelt is unoccupied). In addition, the wireless signal emitted by such seatbelt monitoring systems may not be received by a vehicle controller due to interference caused by, for example, a nearby antenna tower. As a result, the wireless seatbelt monitoring system may fail to properly indicate a change in seatbelt latch status.
It should thus be appreciated that it would be desirable to provide a wireless seatbelt monitoring system that generates unlatched seatbelt alerts for occupied seats only. It would also be desirable that such a wireless seatbelt monitoring system be configured to perform remedial steps if a wireless signal fails to reach the vehicle controller (e.g., resend the wireless signal and, if appropriate, generate an error alert). Other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.